The present invention generally relates to the field of power converters, and, more particularly, to a portable, dual input AC and DC to programmable DC output power converter.
As PC notebooks, PADS, cell phones and the like, continue to grow in popularity, so too does the need for more low cost, compact, power supplies to power these devices. Today, most manufacturers of mobile devices typically include plug-in power adapters along with these mobile devices to help facilitate their customers"" power supply needs.
However, there exists a need for a power converter that resolves the system management problems associated with carrying all of the different power supply components necessary to power a wide variety of mobile or portable devices. Moreover, such a power converter would advantageously encompass serving the power supply needs of several different mobile devices by supplying a regulated DC output voltage, responsive to either an external AC or external DC input voltage. Also, such a power converter would have power storing capabilities which allow the power converter to deliver a constant uninterrupted DC output voltage to a user-connected mobile device whenever the external input voltages are momentarily cut off.
The present invention achieves technical advantages as a power converter delivering a constant, regulated DC output voltage that may be derived distinctly from two separate external input voltages, an AC input voltage or a DC input voltage, and in addition, from a separate, detachable battery pack. The detachable battery pack advantageously allows the power converter to automatically and continuously deliver the regulated DC voltage to the mobile device whenever each external input voltage is unreliable or is temporarily removed. Additionally, the power converter also utilizes a portion of the regulated DC output voltage to conveniently recharge the battery pack during normal operation.
In one embodiment, the present invention is a power converter comprising a power supply circuit and a selectively removable storage circuit. The power supply circuit includes a pair of input filter circuits, each adapted to filter respective AC and DC input voltages provided to the power supply circuit and providing a pair of filtered output voltages. The power supply circuit also comprises a DC-to-DC converter and an AC-to-DC converter, each providing a DC voltage output. The power supply also further comprises a shared DC circuit receiving coupled to the respective DC outputs of the DC-to-DC converter and the AC-to-DC converter. The shared DC circuit provides two regulated DC output voltages, of opposite polarities, at two respective output terminals thereof. The shared DC circuit is also adapted to allow users to selectively program the regulated output voltage, via a programmable key, to conveniently match the voltage and current specifications of their mobile devices.
The detachable battery pack comprises a re-chargeable battery, a battery charger for delivering a charge current to the re-chargeable battery, and a switching circuit comprising a pair of switches and an inverter gate for controlling the charging function of the battery pack. The battery pack is adapted to tap the output terminal of the power supply circuit during normal operation via a common connector plug for recharging. Advantageously, the battery pack can serve as a secondary source of DC input power, in turn, allowing the power supply of the power converter to continuously deliver power to a user-connected device even if each external input voltage is temporarily interrupted or removed.